Roller bearing



Oct. 14, 1941. T- L ROBlNSQN 2,259,325

ROLLER BEARING Original Filed Deo. 23, 1939 2 l I /4 /7 /4 if 22 5 f" '2.5 [i V535/My@ Zin v4 I I I v2 /4 -/j j /j/M 'M @ff' L9 A? l- -E-E.

(fr 7;" M) 2^ Arr RNEY Patented oci. i4, i941 UNITED sTATEs rPATENT oFFicE 310,684. Divided and this application March 19, 1941, Serial N0. 384,049

7 Claims. (Cl. 308-216) This invention relates to roller bearings ofthe vcylindrical roller or needle type.

This application for patent is a division of an application for patent by the same inventor illed December 23, 1939, Serial No. 310,684.

Roller bearings of the prior art generally bind or tend to bind when in service from misalignment and/or inaccuracy of manufacture, and, when in use misaligned and/or imperfect roller bearings develop frictin between the rollers and the inner race mem ers and/or between the rollers and the outer race members. The raceways of the inner and outer race members are generally hardened during manufacture to such a degree, that, when binding develops from misalignment and/or inaccuracy of manufacture. long periods of operation are required to wear the bearing to normal operating freeness.

In high-speed installations or service, the wearing-in of roller bearings often causes overheating of the bearings which expands the various elementsthereof to such a degree that either freezing occurs or irreparable damage is done to the raceways or to the rollers thereof.

Due to misalignment or inaccuracy of manufacture, portions of the hardened annular edges of the inner and outer race members often chip or spall oif near the ends of the rollers due to extremely heavy concentrated loads applied to the race -members at or near the ends of the rollers. Chipping or spalling off of the race membars is more apt to occur in roller bearings which are assembled without suiiicient clearances between the rollers and the race members particularly when such roller bearings are run under heavy loads with the outer and inner race members in slight misalignment caused by shaft and v pillow block misalignment or by bearing support deflection under conditions of heavy loading.

With the foregoing in view, the primary object of the invention is to provide an improved cylindrical roller or needle-type roller bearing which will accommodate itself to reasonable inaccuracies in manufacture and/or misalignment in installation with relatively short wearing-in periods and without the hazard of the chipping or spalling oif of the annular edges of the inner and outer race members under abnormal stresses to which the race members of the roller bearings are subjected when running under conditions of 50 slight inaccuracies of manufacture and assembly and/or misalignment in their installation.

Another object of the invention is to provide a roller bearing having zone hardened inner and outer race members which are relatively softer at 65 the sides of the raceways than at the center thereof which permit plastic deformation of-tbe race members into convex surfaced raceway: during the wearing-in" whereby to reduce friction and the area of contact between the race members and the rollers to aminimum.

Another object of the invention is to provide a roller bearing having the center of the raceways of the inner and outer race members relatively harder than the outer sides of the said raceways whereby to permit the bearing to wear its roller paths slightly convex without chipping or spalling oil of the raceways near the outer annular edges thereof and without damage to the rollers thereof.

Another object of the invention is to provide a novel roller bearing having the ability to wear itself without damage-into free running condition in cases where there has been a slight misalignment of the race members or where there has been inaccuracy in the manufacture of the component parts thereof.

Other objects of the invention will become apparent by reference to the following detailed description taken in connection with the accompanying drawing, in which:

Fig. 1 is a cross sectional view of a roller bearing embodying the invention having a shaft 30 mounted through the inner race member thereof.

Fig. 2 is an enlarged fragmentary view of .the roller bearing disclosed in Fig. l showing the zone hardening of the outer and inner race member thereof.

Fig. 3 is a cross sectional view of the roller bearing disclosed in Fig. 1 after it has been in use under conditions of slight misalignment or inaccuracy of manufacture.

Fig. 4 is an enlarged fragmentary cross sec- 40 tional view of the roller Ibearing showing in detail the convex raceways created after the bearing has been run-in under conditions of slight misalignment or inaccuracy of manufacture.

Referring now to the drawing wherein like numerals refer to like and corresponding parts throughout the several views, and with particular reference to Figs. 1 and 2, the roller bearing generally designated by the numeral IIJ is composed of an outer race member I I, an innner race member I2, and a plurality of rollers I3 disposed between said race members II and I2, the said rollers I3 being retained in operating relationship with respect to the raceway I I0 of the outer race member Il by means of retainer rings I4. The bearing I 0 is indicated in Fig. l with a shaft I6 period of the bearing 2 iltted within the inner race member I2. The raceway I| of the outer race member II and the raceway |20 VYof the inner race member I2 are zone hardened at I0 preferably as diagrammatically indicated by shading disposed normal to the raceways IIO and |20 throughout the drawing; the deeper the' shading, the greater degree of hardness and the deeper the hardening of the raceway.

Th outer and inner race members II and I2 are preferably provided with oil grooves I1 and I8 respectively and each race member is provided with an oil bore I9 and 20 respectively communicating between the said oil grooves I1 and I8 and the raceways I|0 and |20. The outer race member II is provided with counterbores 2| at the side thereof to accommodate the retainer rings I4 which have an outer sloping periphery |40.

After the zone hardening the raceway I|0 of the outer race member II, the rollers I3 are assembled therein and a retainer ring I4 is placed in the counterbores 2| at each side of the said race member II. The outer annular rim 22 of each side of the outer race member is then peened, pressed or rolled over the sloping periphery |40 of the retainer rings I4 whereby to hold the retainer rings I4 and the rollers I3 in the desired assembled relationship with respect to the outer race member After the outer race member II is completely assembled as hereinbefore described, the inner race member I2 is telescoped therewithin; the raceway |20 of the inner race member I2 having been zone hardened at IB similarto the zone hardening of the raceway |I-0-of the outer race\ member II.

The zone hardening of the outer and inner race members and I2 may be accomplished electrically by the induction method or by any other method knownA in the art or later discovered, it being essential that the intensity of the hardening of the said outer and inner race members II and I2 be substantially as diagrammatically indicated by the shading I6 throughout the drawing; the deeper the shading I6 the harder and deeper the hardening of the said race members. By reference to Fig. 2, it will be noted that the sides of the raceway ||0 and ||0 and the sides of the raceway |20 at |200 are relatively softer than the central portion of the raceways I|0 and |20, and that the annular corners 23 are substantially unhardened, all of which contributes to accomplish the beneficial results herein set forth.

Inasmuch as no claim is made herein to the particular method which is employed to harden the raceways I I0 of the outer race member I I and the raceway |20 of the inner race'member I2, any method of hardening may be employed to produce the novel bearing herein disclosed having the sides of the raceways softer than the center thereof. It is also preferable and essential that the rollers I3 of roller bearings embodying the invention be slightly harder than or at least as hard as the thickness of the central portion of the raceways I|0 and |20.

When a bearing I0 has its raceways |I0 and |20 of its race members II and I2 hardened as hereinbefore described and the said bearing I0. which is designed v'to run with its roller in alignment is caused to run with its rollers on a by inaccuracy of manufacture, the raceways ||0 and |20 tend to bind andexcessive pressure is developed against the raceways I|0 and |20 near the sides thereof. Inasmuch as the sides I |00 and skewV by misalignment in installation of the bearing or' |200 of the raceways I|0 and |20 respectively are relatively soft, the bearing -I0 readily wearsin" at |I50 and |200 which causes the raceways ||0 and |20 to assume a convex 4cross section as best shown in Fig. 4. Thus the usual long and destructive wearing-in period is avoided by employing the invention.

Also, because'of the fact that the annular corners 23 of the bearing I0 are not hardened to any particular degree, the frequent failure of a bearing, which often begins by the corners 23 of the outer raceway .I2 spalling or chipping oil under heavy loads or when operating under conditions of misalignment, is generally avoided.

The assembly of bearings is simplified by the instant invention inasmuch as the outer annular rims 22 of the outer race member I I remain soft and ductile after the raceway ||0 of the outer race member II is hardened and are capable of being rolled, peened or pressed over the sloping periphery |40 of the retainer rings I4.

A bearing I0 hardened as herein described with relatively softer sides to its raceways than the center thereof readily forms itself during "wea-ring-in into a bearing having convex raceways which, although known to be extremely desirable, was not heretofore economically possible in roller bearings manufactured in large production for sale in highly competitive markets.

Therefore, the novel roller bearing herein disclosed has superior wearing-in qualities and has raceways that will not spall or chip off under heavy loading or while operating under conditions of misalignment and will shape itself during use into a bearing having desirable convex raceways. thus producingl a more efficient and effective roller bearing as it wears as compared to the usual roller bearing which becomes less effective as a result of wear.

Rather than let the bearings wear-in after being placed in service, they may be run on suitable jigs or running-in blocks at the factory with the raceways positioned slightly out of alignment. Thus, a highly desirable bearing having convex surfaced-raceways can be manufactured at a silght expense over the normalcost of producing like roller bearings having parallel raceways and at a fraction of the expense of machining or grinding the raceways to a convex surface. In the less expensive roller bearings the running-in" would take place in service rather than at the factory.

Although but one embodiment of the invention has been disclosed and described in detail, it is to be understood that many changes in the size, shape, arrangement and detail of the various parts thereof may be made without departing from the spirit of the invention, and it is not intended to limit the scope of the invention other than by the terms of the appended claims.

I claim:

1. A roller bearing of the class described in which the race members are hardened at their raceways harder at the Icenter of the said raceways than at the sides thereof whereby to admit of plastic deformation ofsaid raceways into contion developed when the bearing is run under conditions of inaccuracy of manufacture or misalignment of the raceways thereof.

3. A roller bearing of the class described in which the race members are hardened only at their raceways and then harder at the center of the said raceways than at the sides thereof whereby to admit of plastic deformation of said raceways into convex surfaces when the bearing is run under conditions of inaccuracy of manufacture or misalignment of the raceways thereof.

4. A roller bearing of the class described in which the race members are hardened only at their raceways and then harder at the center of the said raceways than at the sides thereof whereby to materially reduce wearing-in time chipping of the said raceways at the said annular corners thereof when running under heavy loads.

6. A roller bearing of the class described in which the race members are hardened at their tially unhardened at the annular corners of the required and friction developed when the bearing is run under conditions of inaccuracy of manufacture or misalinment of the raceways thereof.

5. A roller, bearing of the class described in which the race members are hardened at their raceways harder at the center of the said raceways than at the sides thereof and left substantially unhardened at the annular corners of the said raceways whereby to admit of plastic deformation of said raceways into convex surfaces when the bearing is run under conditions of inaccuracy of manufacture or misalignment of the raceways thereof and to prevent spalling and said raceways whereby to materially redu'ce Wearing-in time required and friction developed when the bearing is run under lconditions of inaccuracy of manufacture or misalignment of the raceways thereof and to prevent spailing and chipping of the said raceways at the said annular corners thereof when running under heavy loads.

7. In a roller bearing of the class described, an outer race member hardened to a greater degree of hardness at the center of the raceway thereof than at the sides of the said raceway thereof and axially counterbored at both ends to receive retainer rings leaving unhardened annular outer rims at the said ends of the said race member, a retainer ring having a sloping outer periphery positioned in the said counterbore, the said annular outer rims being formed over the said retainer rings whereby to hold the retainer rings and rollers guided thereby in operating relationship with respect to the said outer race member.

THOMAS L. ROBINSON. 

